The brightness of indoor space often needs adjustment in order to adapt to different lighting needs due to the functional change of the space or color and reflectivity of different finish materials. It is known in the prior art to alter the illumination level of a space. Movable light fixtures, such as desk or floor lamps, or fixed light fixtures, such as ceiling/wall mount fixtures, can be added or changed. However, these solutions provide limited amount of change in illumination level and often the effect is localized, or require the help of electricians.
As an alternative to the above methods, there are a few lighting devices which incorporate the idea of lighting units that can be added or removed to alter the illumination level. Proposed lighting devices could be also useful for their general illumination purposes, but they are more suitable for the applications where their decorative or other functional purposes are intended. For example, there are disclosures which use reconfigurable lighting modules such as modular lighting tubes (U.S. Pat. No. 7,217,023, U.S. Pat. Appl. Publ. No. 2012/0201021 and U.S. Pat. No. 4,581,687), or modular lighting tiles (US Pat. Appl. Publ. No. 2012/0224373), but their specific geometry of module limits the module's connectivity and possible assembly configurations. Moreover, the disclosures above are intended to be used as other architectural elements rather than general illumination devices (U.S. Pat. No. 4,581,687 and US Pat. Appl. Publ. No. 2012/0224373). The light source of the prior art above is located only at the end (U.S. Pat. No. 7,217,023), or only in front or back (US Pat. Appl. Publ. No. 2012/0201021 and US Pat. Appl. Publ. No. 2012/0224373), providing directional illumination and causing shaded spots or non-illuminated areas within the fixture. Furthermore, in each disclosure, modules may be connected to one another in a single connection method. In one method, they are directly connected to one another with male/female fasteners (U.S. Pat. No. 4,581,687) or magnets (US Pat. Appl. Publ. No. 2012/0224373). When using a fastener, due to the fact that each fastener accommodates only one other module and the fastener is attached to each end of the tube, the connection pattern is predominantly two dimensional and linear with limited number of possible configurations (U.S. Pat. No. 4,581,687). For this particular disclosure, a one-to-one connection was intended to achieve the appearance of a continuous line of fixtures with apparent seamless joints. Lighting tiles with magnets on the edges can accommodate direct connection of four modules on all sides, but the connection pattern only allows for two-dimensional surface applications (US Pat. Appl. Publ. No. 2012/0224373). Alternatively, modules are connected indirectly via distinct connectors with additional end cap, locking rings and a spacer (US Pat. Appl. Publ. No. 2012/0201021). In this case, depending on the intended shape of assembly and number of modules to be connected, connectors with specific shapes with specific number of sockets/sleeves (US Pat. Appl. Publ. No. 2012/0201021 and U.S. Pat. No. 7,217,023) are required. Therefore, the freedom of reconfiguration is limited within the number of different connectors in use. Due to the specific connectors required for the predetermined connection pattern and many connection elements required, the connection system becomes complicated and non-illuminated connectors make up a significant part of the assembly, as they are bigger than the tubes in diameter, and bulkier.
Other known prior art that uses the system of lighting modules are illuminated modular blocks (U.S. Pat. Nos. 7,731,558 and 7,322,873), daisy chain LEDs and track lights. Modular blocks are designed to be a set of toys. They are not intended to provide general illumination with their singular light source, but designed to have a blinking and glowing effect. Due to the exposed male and female conductors or a plurality of magnetic fasteners on each surface of the block, significant amount of each surface cannot be illuminated or is obscured. Furthermore, when two blocks are connected, at least two surfaces of the blocks are entirely obscured as they are attached together, which is worsened with each connected block. The alternate embodiment of U.S. Pat. No. 7,322,873, an illuminated toy system consisting of illuminating ball and connector stick uses distinct connectors and spherical lighting modules with a plurality of connecting apertures. Due to the non-illuminated connecting apertures and conducting connectors occupying a large portion of the surface area and volume of the module shell, significant amount of the module's surface is obscured or cannot be illuminated, and creates uneven lighting. Daisy chain LEDs are structurally dependent on the mounted surface for accent or supplemental lighting, allowing for only end-to-end connection. Track lights allow for altering the number of fixtures, but on a predetermined linear path, therefore its flexibility in application is limited within the length and shape of the track.